7th Demon Prince Jilbagias' Chronicle of Demon Kingdom Toppling - Chapter 94.1 - The Mask of Prince

Bad End Night is a novel by Hitoshizuku-P, based on a series of Vocaloid songs, the NighT Series. The plot revolves around eight actors trapped in a never-ending play, seeking a way to escape.

A story of time-travel. Sly and cunning, she unexpectedly became a sickly noble lady whose fiancé is merciless and demotes her to a lowly concubine. She sneers and bravely breaks off the engagement. To hell with scumbags, marry heirs to lords, blind the courts with her brilliance.

The world has changed into something like a game.

It resembles a survival virtual reality game where people were attacked by zombies and monsters.

And I was the last user of that game.